Server virtualization in the data-center has increased the density of networking endpoints in a network. Together with the need to migrate VMs anywhere in the data-center this has surfaced network scalability limitations (layer 2, cross IP subnet migrations, network renumbering).

The industry has turned its attention towards overlay networks to solve the network scalability problems. The overlay network concept defines a domain connecting virtual machines belonging to a single tenant or organization. This virtual network may be built across the server hypervisors which are connected over an arbitrary topology. This talk will give an overview of the problems sought to be solved through the use of overlay networks, and discusses the active proposals such as VxLAN, NVGRE, and DOVE Network. We further will delve into options for implementing the solutions on Linux.